DuetoparticularlyactiveworkdevelopedintheCMS.workinggroupbymostofthe participants, interesting results have been got. The most significânt contributions were:- The discovery of the CMS sources- The finding of restorer genes for "difficult to restore" CMS- The analysis of the genetic determinism of the fertility restoration of new CMS. _ The comparison of ihe cMS by genetic, molecular, or agronomical ways. Therefore, evidence is that a lot of studies are still necessary to differentiate the CMS sources. I-itay, some of the 42 cMS sources reported may be identical. It is clear that complementary genetic studies have to be performed. Molecular studies on Mt DNd proved to bË powerfuliJob and fast techniques, either to separate the CMS or to explain the mechanisms of the cytoplasmic male sterility. Another aspect to be studied is the identification of the specific Rf genes in the different cMs. With this objective, several participants have already started crosses between restorer genotypes to prepare allelism tests. Ttrii could be one of the proposals of the w. G., for the next period.